Location tracking using IR throwies

[Joe] and his team hacked together some location tracking using IR throwies for their final project. The challenge they undertook was to find a way to track the orientation of a sculpture in the form of a rotating metal cube. The end result dips its toe into the augmented reality pool but the methods are what interest us.

They wanted this to work day or night so contrast would be a major issue if working completely with image manipulation. Having a simple way to pick out the corners of the monotone block would make this process a breeze. They ended up using magnetic throwies that have an infrared LED which can easily be picked up by a webcam no matter what the ambient light issues happen to be.

After the break you can see these guys out in the wild testing the system. We’d like to note the diffusers used in the project. We’re used to seeing ping-pong balls as diffusers but this is the first time we’ve noticed Styrofoam balls being used.

@xchip I completely agree. This practice is ridiculous, and I think its pretty much encouraged that you throw them on moving items such as trains in many instructables..

I don’t know how anyone thinks that purposely throwing heavy metals in the environment is a good idea. The CR2303 batteries have found themselves in so many useless items that just end up in the trash when spent. Such as flicking candle LEDs..

Throwies as a term doesnt necesserely mean u throw them away. it means you throw them…u can still dispose of them in a sensible matter afterwards. its very presumptious to think that it is bad just because of some senseless people.

I found a way to recharge Li coin cells, seems that putting them in a case then freezing them and charging at 0.5mA works most of the time.
The capacity is pretty high, near 80% but this can only be done safely maybe twice..